Spacetime Fluid and the Conservation of Angular Momentum -- An Analysis of Rotational Phenomena Based on the Hypothesis of Differential Descent

Starting from the simplest mechanical observations, this paper introduces two fundamental concepts: translational descent and differential descent. It attributes all rotational motion to a geometric offset between the point of action of an external force and the centre of mass of the body. Furthermore, it introduces the “spin averaging effect”, by which rapid self‑rotation smooths out the biased forcing over a complete cycle. Based on dimensional analysis, we propose a distribution function F(ω) = 1/(1+(ω T)^2) that quantifies the fraction of differential descent not cancelled by spin, where the characteristic time T = √I/(mgh) is determined solely by the body’s geometric parameters. Finally, we link this phenomenological model to the spacetime fluid hypothesis: matter is a local vortex in the spacetime fluid, and angular momentum conservation is not an a priori axiom but an emergent energy‑release path under constrained conditions. The framework requires no advanced mathematics and yields predictions that can be qualitatively tested with simple experiments.